1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/compiler.h> 3 #include <fcntl.h> 4 #include <signal.h> 5 #include <unistd.h> 6 #include <sys/stat.h> 7 #include "util/dso.h" 8 #include "util/map.h" 9 #include "util/symbol.h" 10 #include "util/debug.h" 11 #include "util/machine.h" 12 #include "tests.h" 13 14 /* 15 * This test is to check whether a bad symbol in a module won't split kallsyms maps. 16 * The main_symbol[1-3] should belong to the main [kernel.kallsyms] map even if the 17 * bad_symbol from the module is found in the middle. 18 */ 19 static char root_template[] = "/tmp/perf-test.XXXXXX"; 20 static char *root_dir; 21 22 static const char proc_version[] = "Linux version X.Y.Z (just for perf test)\n"; 23 static const char proc_modules[] = "module 4096 1 - Live 0xffffffffcd000000\n"; 24 static const char proc_kallsyms[] = 25 "ffffffffab200000 T _stext\n" 26 "ffffffffab200010 T good_symbol\n" 27 "ffffffffab200020 t bad_symbol\n" 28 "ffffffffab200030 t main_symbol1\n" 29 "ffffffffab200040 t main_symbol2\n" 30 "ffffffffab200050 t main_symbol3\n" 31 "ffffffffab200060 T _etext\n" 32 "ffffffffcd000000 T start_module\t[module]\n" 33 "ffffffffab200020 u bad_symbol\t[module]\n" 34 "ffffffffcd000040 T end_module\t[module]\n"; 35 36 static struct { 37 const char *name; 38 const char *contents; 39 long len; 40 } proc_files[] = { 41 { "version", proc_version, sizeof(proc_version) - 1 }, 42 { "modules", proc_modules, sizeof(proc_modules) - 1 }, 43 { "kallsyms", proc_kallsyms, sizeof(proc_kallsyms) - 1 }, 44 }; 45 46 static void remove_proc_dir(int sig __maybe_unused) 47 { 48 char buf[128]; 49 50 if (root_dir == NULL) 51 return; 52 53 for (unsigned i = 0; i < ARRAY_SIZE(proc_files); i++) { 54 scnprintf(buf, sizeof(buf), "%s/proc/%s", root_dir, proc_files[i].name); 55 remove(buf); 56 } 57 58 scnprintf(buf, sizeof(buf), "%s/proc", root_dir); 59 rmdir(buf); 60 61 rmdir(root_dir); 62 root_dir = NULL; 63 } 64 65 static int create_proc_dir(void) 66 { 67 char buf[128]; 68 69 root_dir = mkdtemp(root_template); 70 if (root_dir == NULL) 71 return -1; 72 73 scnprintf(buf, sizeof(buf), "%s/proc", root_dir); 74 if (mkdir(buf, 0700) < 0) 75 goto err; 76 77 for (unsigned i = 0; i < ARRAY_SIZE(proc_files); i++) { 78 int fd, len; 79 80 scnprintf(buf, sizeof(buf), "%s/proc/%s", root_dir, proc_files[i].name); 81 fd = open(buf, O_RDWR | O_CREAT, 0600); 82 if (fd < 0) 83 goto err; 84 85 len = write(fd, proc_files[i].contents, proc_files[i].len); 86 close(fd); 87 if (len != proc_files[i].len) 88 goto err; 89 } 90 return 0; 91 92 err: 93 remove_proc_dir(0); 94 return -1; 95 } 96 97 static int test__kallsyms_split(struct test_suite *test __maybe_unused, 98 int subtest __maybe_unused) 99 { 100 struct machine m; 101 struct map *map = NULL; 102 int ret = TEST_FAIL; 103 104 pr_debug("try to create fake root directory\n"); 105 if (create_proc_dir() < 0) { 106 pr_debug("SKIP: cannot create a fake root directory\n"); 107 return TEST_SKIP; 108 } 109 110 signal(SIGINT, remove_proc_dir); 111 signal(SIGPIPE, remove_proc_dir); 112 signal(SIGSEGV, remove_proc_dir); 113 signal(SIGTERM, remove_proc_dir); 114 115 pr_debug("create kernel maps from the fake root directory\n"); 116 machine__init(&m, root_dir, HOST_KERNEL_ID); 117 if (machine__create_kernel_maps(&m) < 0) { 118 pr_debug("FAIL: failed to create kernel maps\n"); 119 goto out; 120 } 121 122 /* force to use /proc/kallsyms */ 123 symbol_conf.ignore_vmlinux = true; 124 symbol_conf.ignore_vmlinux_buildid = true; 125 symbol_conf.allow_aliases = true; 126 127 if (map__load(machine__kernel_map(&m)) < 0) { 128 pr_debug("FAIL: failed to load kallsyms\n"); 129 goto out; 130 } 131 132 pr_debug("kernel map loaded - check symbol and map\n"); 133 if (maps__nr_maps(machine__kernel_maps(&m)) != 2) { 134 pr_debug("FAIL: it should have the kernel and a module, but has %u maps\n", 135 maps__nr_maps(machine__kernel_maps(&m))); 136 goto out; 137 } 138 139 if (machine__find_kernel_symbol_by_name(&m, "main_symbol3", &map) == NULL) { 140 pr_debug("FAIL: failed to find a symbol\n"); 141 goto out; 142 } 143 144 if (!RC_CHK_EQUAL(map, machine__kernel_map(&m))) { 145 pr_debug("FAIL: the symbol is not in the kernel map\n"); 146 goto out; 147 } 148 ret = TEST_OK; 149 150 out: 151 remove_proc_dir(0); 152 machine__exit(&m); 153 return ret; 154 } 155 156 DEFINE_SUITE("split kallsyms", kallsyms_split); 157